The investment is half of the projected £50m cost of the planned park in Shinfield next to the M4 motorway.
The park, which will also include offices, is expected to take up to 25 years to fully complete.
Wokingham Borough Council granted the university planning permission for the project, masterplanned by Scott Brownrigg, in 2010.
The University and Council have also already secured an investment of almost £25m for the Shinfield Eastern Relief Road, a key infrastructure development to underpin access to the Science and Innovation Park as well as the Shinfield West housing development.
Sir David Bell, Vice-Chancellor of the University of Reading, said: “There is a substantial market in the region for such a facility, with no dedicated science park currently operating in the Thames Valley or London.
“We expect strong demand from both UK and international companies seeking a prominent Thames Valley location, while the Science Park will also be the natural choice for London-based companies that are looking for space to expand as well as emergent Thames Valley SMEs.”